Indicator-Based Assessment of EPC Data Accessibility and Usability in Catalonia, Galicia, and the Basque Country

This dataset contains the results of an indicator-based assessment of the accessibility and usability of Energy Performance Certificate (EPC) information systems in three Spanish Autonomous Communities: Catalonia, Galicia, and the Basque Country. The study examines whether the decentralised management of EPC registers produces regional differences despite a common national and European regulatory framework. The framework comprises two analytical dimensions, eleven assessment criteria, and forty-five operational indicators covering access, data availability, retrievability, visualisation, openness, interoperability, dataset comprehensiveness, harmonisation, and metadata quality. Data were collected between April and December 2025 through direct observation of official EPC registers, institutional websites, open-data portals, geoportals, visualisation platforms, and downloadable datasets. Each region was independently assessed by two researchers using a common protocol, and discrepancies were resolved by consensus. The workbook includes indicator-level scores, aggregated results by criterion and dimension, weighted overall scores, comparative tables, and graphs. Scores range from 0 to 100, with higher values indicating better accessibility or usability. The overall weighted scores are 83.27 for the Basque Country, 77.89 for Catalonia, and 64.62 for Galicia. The dataset can be used to reproduce the comparative results reported in the associated article, identify strengths and weaknesses in regional EPC information systems, and support future applications of the framework in other territorial or national contexts.